Occlusion of the Crop. 243 



The disease can sometimes be cured only by an incision into 

 tlie crop. This operation also seems indicated in pendulous 

 crop, provided the catarrhalcondition has already disappeared. 



Catarrh of the crop in pigeons due to the early removal of 

 their young- ones may be cured rapidly by substituting other 

 young ones. 



Literature. Klee, Gefliigelkrankheiten, 1905, 76.— Ziirii, Gefliigelkrkhten., 

 1882, 76. 



(b) Occlusion of the Crop. Obstructio ingluviei. 



{Hard crop, indigestion iugluviale [French].) 



Etiology. Occlusion of the crop is frequently due to 

 overfeeding, especially with dry grains (millet, corn, peas, oats) 

 or with a feed containing much bran or chopped straw. In 

 water fowl the disease follows upon the ingestion of certain 

 aquatic plants (chara, cynodon, triticum repens, corex) or of 

 ailanthus glandulosa. Young pheasants sometimes contract the 

 disease after the ingestion of numerous insect larvae. Some- 

 times foreign bodies (pieces of metal, stones, pieces of glass, 

 pieces of bones, fragments of Qgg shells) or many small stones 

 cause the disease, which exceptionally may be produced by ani- 

 mal parasites (Railliet and Lucet). 



Symptoms. Obstruction of the crop manifests itself by the 

 fact that the animal becomes listless, it repeatedly opens the 

 beak and the latter sometimes discharges an ill-smelling fluid. 

 The appetite is absent either from the start, or after some time 

 if the obstruction is due to a foreign body. The crop appears 

 enlarged; its wall is tense, elastic, sometimes doughy, some- 

 times hard in consistency (socalled hard crop), depending 

 upon the mass of accumulated food and upon the amount 

 of gases that have formed. Foreign bodies in the crop 

 may l)e felt through its wall or may be demonstrated by a 

 Roentgenograph. 



Course. Obstruction of the crop rarely disappears spon- 

 taneously. If nothing is done, chickens usually die of exhaus- 

 tion after a few days ; w^ater fowl, however, succumb to suffoca- 

 tion after a few hours (Dupont). This difference in the 

 course can perhaps be explained 1)y the fact that the crop 

 of chickens is really an extrusion directed outward, while the 

 crop of water fowl is a circular dilation of the esophagus, which 

 may easily compress the trachea. Occasionally rupture or per- 

 foration of the crop occurs. Rivolta and Delprato saw the for- 

 mation of an enormous crop (socalled pendulous crop) in a 

 hen (Kitt). 



Treatment. If the contents are not too hard, massage of 

 the crop, and kneading of the contents towards the beak, are in- 



